The great Sindarin Lambengolmo (linguist), the purported author of much of Tolkien’s linguistic writings (PM/395, WJ/396). His name is simply pengolodh “teacher of lore” used as a name (PE17/139-140).
Conceptual Development: In Silmarillion drafts from the 1930s, his name was N. Pengolod, where various footnotes indicate he may have been the author, or at least the compiler, of the Silmarillion itself (LR/113, 228, 277-278). The final -d matches the orthographic conventions of this period, where [ð] was sometimes represented by d (PE22/34, 67). In some later writings, Tolkien considered changing his name to Thingódhel (WJ/419 note #25).
{ð} _n. _a teacher of lore, teaching sage, doctor. Also used as a title or name. >> golodh